Driving mechanism for elevators and the like.



L. ATWOOD.

DRIVING MECHANISM FOR ELEVATORS AND THE LIKE.

APPLICATION FILED APR. 3, 1913.

Patented Sept. 8, 1914.

UNITED sTAtrnsrnrEN'r OFFICE.

I LEONARD A'IWOOD. OF FARMING'IDN, MAINE.

DRIVING MECHANISM FOR ELEVATORS AND THE LIKE.

Specification of Letters Patent.

Patented Sept. 8, 1914.

7 Application filed April 3, 191a. Seria1No.758,578.

that pass over a hoisting drum.

The present invention has for its'special purpose to avoidthat a heavy car and counterweight is required to produce the necessary'friction for efiecting the work. This in time consumes an unnecessary quantity of power to operate the elevatorliftor hoisting apparatus. Certain machines. require 600 pounds of dead load to produce su'fiicient friction to lift 100 pounds of live loadwhich makes the car very heavy and the counter.

weight accordingly so.

By winding the cables over the hoisting drum one full turn and one half turn, in conjunction with the detailed construction hereinafter described, increased friction of the cables on the drum is produced which permits of using a relatively light car and counterweight. Idlers and secondary pul-' leys for the cables are avoided and the car stops automatically at the desired point, which is not the case when the cables are tending to slip on the drum. The invention further consists in the construction of the drum and its arrangement on the motor shaft which is splined to one. hub while a stationary feed shaft with outer thread surrounds part of the motor shaft and en ages the inner threaded portion of a second hub of the drum whereby the drum is adapted to move to and fro in a forward and backward direction, all as will be fully described hereinafter with reference to the accompanying drawing in which:

Figure 1 represents diagrammatically an elevator embodying the rope or cable arrangement for obtaining high friction. Fig. 2 illustrates the drive mechanism for an elevator in side elevation, and Fig. 3 is a longitudinal section on line 3-3 of Fig. 2.

Similar characters of reference like parts in all the figures.

In Fig. 1 of the drawing an elevator is diagrammatically shown in which a repre- Suspended from oneend of the noto shaft it for applying power.

denote sents a hoistingdrum and b the rope or cable passing once fully around the drum and over the'top half portionof the same. rope is the counterweight 0 while the car d is suspended from the other rope-end. This diagrammatical figureis purposed to. simply illustrate. the arrangement of the ropes or cables on'the hoisting drum. Therope or cable 6 friction than is produced if-the rope passes only over the top half portion of the drum.

For rendering this rope arrangement possible the hoisting drum-is provided with one continuous helical thread having a continuous groove e. as shown in Fig. 2.

The driving mechanism illustrated in Fig. 2 comprises a substantial framework 7. Upon the-part of the frame shown to the left-"there "is-mounted reducing mechanism i nclo sed in the reducing case g. In connection with thereducing mechanism the A bearing-'11 is mounted'on the frame part shown to the right in Fig. 2. The reducing mechanism is provided with the driving shaft j for the drum extending over to the bearing 2'. The shaft 7' has a longitudinal groove 7' which serves for splining the shaft to the drum. A threaded feed shaft is surrounds the right portion of the shaft 7' and extends into the bearing 13 where it is permanently secured by means of a screw Z. The drum 0!. is provided with two hubs m, n. The hub m has a lateral slot m through which passes a feather 0. Thus the driving shaft j is splined tothe hub m and the drum moves with it. The hub 11 at. the other side of the drum is interiorly threaded and engages the thread of the feed shaft is whereby, during the rotation of the driving shaft 7' the drum travels along the feed shaft 70 in both a forward or backward direction in accordance with the direction of the rotation of the shaft -j.' In Fig. 2 of the drawing the drum a is shown to have traveled on the feed shaft 7*: and the driving shaft 7' to near the end of the shaft slot j. IVhen the; rotation of the shaft j is reversed the drum travels toward the right because the feed shaft is is permanently secured in the bearing 73.

As previously mentioned the hoisting drum' a has one continuous thread with one continuous helical groove 0. The plurality of cables p, 39 etc., therefore always retain their initial position because the drum perthus produces more than three times the forms a horizontal motion both in a forward and backward direction. leaving the ropes always in the same position relative to the top center portion of the-can, It is evident that the threads of the hoisting drum and its feed shaft must. correspond. Accord: ingly anidle wheel for guiding the ropes is not necessary and completely dispensed with by virtue of the increased frictionproduced by the novel a-rrangenient of the ropes or cables on the 'hoisting drum whereby a lighter car and counterweight 'may be used avoiding thus a large amount of dead Weight andsaving power.

-I claim as m'yjnvention:

1. Driving mechanism for elevators, lifts andhoisting apparatiis,:comp1ising a hoisting drum with threaded hub and helical rope groove, ropes in said groove around the drum, a driving shaft splinedto the drum, and a permanently fixed, eiteriorally threaded feed shaft, loosely on the. driving shaft and engaging the .threadedhub of the drum.

2. Driving mechanism forelevators, lifts, and hoistingqapparatus, comprising a driving shaft with longitudinal spline groove in its inner portion, a permanently fixed, exteriorally threaded feed shaft loosely on the driving shaft, a hoisting drum threaded on the feed shaft. and having a helical rope groove, ropesin said groove around the drum, a hub onthe dnum-with slot and a feather therein traveling in the spline groove.,.-i.

3. Driving drum of elevators and lifts, comprising a drum, a'driving shaft splined to the drum,

a hub on the drum with feather traveling in-th'e spline groove; a second hub on the drum with-interiorthread, and a permav .35 r i i a mechanism for the holstlng nently fiired feed shaft with an exterior thread in operative engagement with innefthread of said second hub.

4. In driving mechanism for. elevators and lifts, a hoisting drum with helical groove, ropes in the said groove Wound around the drum for: avoiding the raising'of dead weight, a driving shaft splined to the drum,

a stationary feed shaft loosely on-the inner portion of the driving shaft, and an" interrorly threaded hub on the drum en-' end gaging the thread'of the=feed shaft.'

Signed at Boston, Mass, March 26th 1913. -.LEONARD ATWOOD.v

Witnesses: Y w 1' Bnnssr'momirmm, p N. M. A'rwoomn the 

